On the TV I changed over to BILSTEIN shocks. I need, still, to add an aftermarket rear anti-roll bar.

The final piece of the equation on my truck is replacing the factory receiver with a TORKLIFT heavy-duty piece as I believe that the wimpy factory piece did not resist "twist" from my similar size/weight trailer as yours.

This is the form I use to check out numbers:

Get all the numbers, and try NickCrowhursts Calculator

Crowhurst Calc: Excel spreadsheet

1. TT Length, Hitch Ball Center to TT Rear Bumper:

2. TT Tongue Weight:

3. TT Hitch Center to Rear Axle Center:

4. TV wheelbase:

5. TV Rear Spring Capacity:

6. TV Rear Overhang (axle center to hitch center):

7. Length of bars:

A. TV Steer Axle, Solo:
[1] TV Steer Axle, Loaded:

B. TV Drive Axle, Solo:
[1] TV Steer Axle, Loaded:

C. TV Weight Bias, FF/RR, Solo:
[1] Loaded:

D. TV Weight, Solo, Gross:

E. TV Weight, Loaded, Gross:

F. TT, Tongue Weight:

G. TT, Axle Weight (all axles):

H. TT, Axle Weight (front):

I. TT, Axle Weight (rear):

J. [TT, Axle Weight (center):]

I. TV, FF, height, solo:

II. TV, FF, height, loaded:

III. TV, RR, height, solo:

IV. TV, RR, height, loaded:

V. TT, height (fenderwell), solo:

VI. TT, height (fenderwell), loaded:

The two dozen numbers can be useful for further tuning or understanding. On my truck I was ready to try modifying the rear suspension by removing the huge single overload spring, one spacer; and add TIMBREN overload replacements in a custom height. Not that you should. The point is, IMO, to keep searching out solutions as you are doing.